Wireless communication technologies are rapidly evolving and being deployed. In some situations, it is possible to obtain wireless connections to multiple (for example, 3G, WiMAX, CDMA2000, EVDO-RevA, HSPA, LTE and GSM) wireless networks at a given location. However, at the given location, one of the types of networks may provide a better wireless connection as determined by a better quality of service (QoS) or signal to noise ratio (SNR). Additionally, one type of network may provide better support of a type of data communication.
Generally, a subscriber device of a wireless network user can only communicate with one type of wireless network at a time. Therefore, the user is not able to take advantage of a better connection provided by a wireless network that the subscriber device of the user is not connected to.
A subscriber can simultaneously communicate with multiple networks if the subscriber constantly powers electronic circuitry required to support the multiple networks. However, subscribers are typically in an environment with limited sources of power—for example, USB data cards cannot draw more than 500 mA of current. Even in a battery powered unit, it is undesirable to provide continuous power to circuitry required to simultaneously support multiple networks in order to maximize the battery life. Without powering multiple network support circuitry, if the subscriber unit changes the type of wireless network it is connected to, the communication between the subscriber unit and the wireless network is disrupted. That is, the communication must be halted for a period of time while the subscriber initiates the connection to the new type of wireless network.
It is desirable for a low-power subscriber unit to monitor existence of multiple types of wireless networks and select the most desirable of the wireless network while minimizing power consumed by the low-power subscriber.